In:
International Endodontic Journal, Wiley, Vol. 54, No. 12 ( 2021-12), p. 2219-2228
Abstract:
To evaluate the antibacterial effect of sonic‐ and ultrasonic‐activated irrigation on bacterial reduction of a dual‐species biofilm in root canals compared to nonactivated irrigation in a laboratory study. Methodology Two hundred and forty extracted human single‐rooted maxillary anterior teeth were divided into two main groups (G, n = 120) according to the initial preparation size of the root canal (G1: size 25, 0.06 taper, G2: size 40, 0.06 taper). Root canals were inoculated with Enterococcus faecalis and Streptococcus oralis . After 5 days, G1 received combined instrumentation (up to size 40, 0.06 taper) and irrigation/activation, whereas G2 received solely irrigation/activation protocols. In both groups, irrigation was performed with sodium hypochlorite (NaOCl 1%) or physiological saline (NaCl 0.9%), using nonactivated syringe irrigation, sonic activation (2 x 30 s) or ultrasonic activation (2 x 30 s). Logarithmic reduction factors (LRFs) of colony‐forming units were analysed separately for dentine‐adherent and planktonic bacteria immediately after irrigation/activation protocols (time‐point 1) or after 5 days of further incubation (time‐point 2) by analysis of variance ( anova ) and post hoc tests (Tukey's HSD, t‐test). The significance level was set at 0.05. Results In G1 subgroups (combined instrumentation with irrigation/activation), LRFs were significantly affected by the applied irrigation solution ( p 〈 .0001), but not by the activation method ( p 〉 .05; anova ). In G2 subgroups (solely irrigation/activation), both, irrigant solution and activation, significantly affected LRFs ( p 〈 .0001, anova ). Sonic activation resulted in significantly higher LRFs than ultrasonic activation ( p 〈 .0001) which had significantly greater reductions than nonactivated irrigation ( p 〈 .05; Tukey's HSD). At T2, strong bacterial regrowth was observed in all groups; however, a significant bacterial reduction was detected for factors instrumentation, irrigant solution and activation ( p 〈 .0001; anova ). Similar LRFs were found for dentine‐adherent and planktonic bacterial cells in all groups ( r = 0.91 at T1, r = 0.8 at T2). Conclusions In this laboratory study on extracted maxillary anterior teeth high‐frequency sonic activation resulted in a greater bacterial reduction compared to ultrasonic activation in groups receiving solely irrigation/activation protocols; however, irrigation using NaOCl and ultrasonic activation also contributed significantly to bacterial reduction compared to the control groups.
Type of Medium:
Online Resource
ISSN:
0143-2885
,
1365-2591
Language:
English
Publisher:
Wiley
Publication Date:
2021
detail.hit.zdb_id:
2020354-8
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